Thursday, September 29, 2022

Guitar Ted's How To: The Rim Taping Reference Post

Okay! You asked for it, now you got it! (Well, a couple of you asked for this) This stems from the comments from my last "How To" post. Anyway, this post will be a reference post more than anything since I have written a bunch already on tubeless tire taping procedures and how I do this.

As with anything, quality materials are everything when it comes to successful outcomes. So, make sure you use a tubeless rim and really high quality rim tape with great valves. Never assume that you can get away with using a not-for-tubeless rim, a duct tape variant, or old, used up valves. 

Want to save money? That's cool. We all do. Read THIS POST for great tips on how to get high-quality rim tape or sealant for your set up. Make sure you read the comments at the bottom for more great tips. 

Side Note: If you are re-using a tire with a lot of old sealant in it, READ THIS POST for tips on how to remove old sealant. 

For more on the preparation of you tire, rim tape installation, and valve core tips, read THIS POST. This is an over-all look at tubeless tire set-up, but the rim taping thing is in there.

More Tips:

Actually putting tape on a rim is an arduous task. My number one tip is to get prepped properly (cleaned rim, great tape, right tools) and use plenty of patience. Taping two rims is not a race. The ordinary rider should expect this to take up to and over a half an hour of your time. I know mechanics that will scoff at that, but they do things trying to be fast and efficient. People that are not mechanics don't have that constraint or need. Take your time taping and get it right.

Tools: I'll say it- a truing stand is your best friend here. You can tape a rim "free style", out of a bike, and you can tape a rim in a bike with it upside down on the floor. But a truing stand, properly affixed to a bench, makes taping a rim waaaaay easier. Obviously a truing stand is good for more than this, so seriously consider that as an upgrade to your shop. 

Technique: The next big thing to add here is technique, and what I do is almost impossible without a truing stand, that's why I recommend a truing stand for your personal shop. I pull the tape gently with my right hand and hold the starting end down with my left thumb in the inner rim well. I pull maybe three inches, carefully align it, and pull it down toward the rim well. At the same time I start sliding my left thumb downward, but this is tricky as you have to not let the wheel rotate. 

Once I lay the tape down on the rim then I use my left thumb or I'll use my right forefinger to press the tape down starting at the furthest point from the roll and working toward the roll. I only push it down in the center of the tape. I don't bother worrying about the edges until later. 

I always put two laps of tape down on a rim. This is to help the tape withstand air pressure at the spoke holes. You could also use something like these Velocity Rim Plugs which would do the same thing. Another product that aims to alleviate the same problem is the WTB Solid Strip. By using these you might get away with one run of rim strip. However; I'd still use two runs of tape, because saving whatever weight using one run would give you, it is not worth it. 

Rim tape should be wide enough that it covers up to where the bead of the tire will sit at a minimum and up to the rim's inner edge if at all possible. Never try overlapping tape to make it "wide enough". Get the right width rim tape instead. 

Other than that, I always start taping at the point 180° from the valve stem. I've seen tape jobs that start near the valve stem, but in my opinion this invites a possible failure. Tape ends are prone to lifting and letting sealant seep between layers of tape or the tape and the rim well. If this occurs near a valve stem, a perfect place for pressure to escape, then you have a big problem. So, why not avoid that possibility and start your tape end at a point the furthest away from that big hole in the rim for the valve? 

That's it. Did I miss anything you wanted to know? (Don't forget to check the links!) Hit me up in the comments.


teamdarb said...

Tape width- this has always been a head scratcher for me. Have you experenced failure due to tape width being only as wide as it need be i.e. a couple of mm beyond spoke holes? I feel this is some long running bike juju like wipe a brake rotor down after touching with your hands. The glue ought to do its job if the surface is prepped clean.

Guitar Ted said...

@teamdarb - Air pressure is a funny thing. This is why I recommend getting tape as wide as the inner rim well is, so that the tire can seal the tape down against the rim. Air pressure will find the weakest link in your tape job and exploit that to find an area of lower pressure. I doubt that most of us could confidently say that we could lay down a tape job so well that there was zero chance that air under high pressure couldn't lift a tape edge if we went a bit too narrow on the tape. It just isn't worth the risk.

That said, some rims, notably the Bontrager fat bike rims they made a few years ago, had a channel extruded into the rim which your tape was to be laid into, covering the spoke holes and not much more. That worked reasonably well from what I have seen and heard. But narrower rims like gravel/most MTB rims couldn't really benefit from a design like that because of the lack of space to do that sort of extrusion and because it would make the rim unnecessarily heavy.

ENB said...

thx for this, and all your other invaluable content.

A further question: How about rims with cutouts, i.e. fatbikes/29+?

I have a mulefut 50 29+ wheel that I bought used a decade ago and have never done anything other than inject sealant into the valve stem occasionally and air it up. The previous owner had used a regular innertube to block the cutouts but there is always what looks to be water leaking out of them. It's been an embarrasingly long time winter project that I've never gotten around to (mostly because the tire never lost air or got a hole) but I would like to strip it this winter and reassemble correctly, including a real cutout liner.

teamdarb said...

Ah, I understand what you mean about the narrow rims. My thought on tubeless definitely come from a fat rim world. What are your thoughts on the "warming" up tape method?

Guitar Ted said...

@ENB - Thank you for reading! On fat bike rims with cut-outs taping is even harder to accomplish well. That's due to the liner which you use for the prevention of air escaping from the cutouts themselves. I know we always used Surly fat bike strips for this, then taped over with the Whisky fat bike rim tape, which was really good. I think Sun-Ringle' has a decent tape as well, but that is harder to get.

it is IMPERATIVE that you put the Surly rim strip in, lay your two runs of tubeless tape over that, and PUT A TUBE IN THE TIRE AND MOUNT IT. (Apologies for "yelling", but this is important) Then air that all up to 15-20psi and let it sit overnight. Later, let the air out, pull only ONE SIDE of the tire off, pull the tube, insert a tubeless valve stem, and introduce sealant. Mount the side of the tire you pried off to get the tube out and air it up.

You'll also likely have a big mess of sealant dried up inside that tire, so you nay want to clean that off first.

Thanks again for reading and good luck with that set up!

Guitar Ted said...

@teamdarb - I am not familiar with that method, but I assume that what "warming up" does is that it softens the adhesive, making it more tacky/sticky. I can see a slight advantage to that, but good tape really doesn't need that. The linked article to the cheap options will lead you to what I consider to be the best tubeless tape I've ever used. The black Tessa stuff, and it lays down really well and has a great "stretch" factor and tackiness.